Author Topic: How to calculate the Solute or Solvent Center Voronoi Indices by OVITO script?  (Read 205 times)

FATEH

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Hi! I am doing Simulation of the metallic glasses I want to anlyse the local Structure of the metallic glass. I want to compute solute and solvent centered VORONOI INDICES by OVITO Python script. How can I do this?

Constanze Kalcher

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Hi,

with the help of the Voronoi analysis modifier you can compute the Voronoi indices of the Voronoi cell of each atom, which are stored as individual particle property.
http://ovito.org/manual/particles.modifiers.voronoi_analysis.html
Analogous to the procedure in the GUI, in a python script you would simply add the Voronoi analysis modifier to your pipeline and set the option "compute_indices=True".
http://ovito.org/manual/python/modules/ovito_modifiers.html#ovito.modifiers.VoronoiAnalysisModifier

Also, there is a ready-to-use code example in the manual which shows you how to calculate the distribution of Voronoi polyhedra in your metallic glass:
http://ovito.org/manual/python/introduction/examples.html

In order to distinguish between different particle types of the center atoms of each coordination polyhedron you can e.g. create a selection based on their particle type.

-Constanze

Sacho

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Dear Constanze

I have a problem about the Voronoi analysis.
How to determine the value of absolute and relative face area threshold, and the edge length threshold?

Thanks
Sacho

Constanze Kalcher

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Dear Sacho,

that completely depends on your system and what you would like to study. In general these parameters can be used to exclude certain edges and faces of a Voronoi cell from the Voronoi index calculation, please also see the paper listed as reference in the manual:
http://ovito.org/manual_testing/particles.modifiers.voronoi_analysis.html
However, if you're unsure about whether you need this option or not, you should leave them at their default value of 0.

-Constanze